Huge email inboxes, lots of fancy features, minimalist interface... these are things that we Gmail users seem to take for granted anymore. Considering that it was produced by what was at the time primarily a search and ad serving company, it seems strange that it was so good on the first try. For years, email clients, especially web-based email clients, had frustrated me with their limited, often broken, functionality and their incredibly small inbox sizes. 10MB? That's it? My hard drive at the time Gmail was released was 50GB! I know drive space isn't cheap when you're talking terabytes, but neither is bandwidth and these email providers don't seem to have any problem providing plenty of that.
There are several things about Gmail that instantly drew me to the service (as soon as I could get an invite that is). First, the 1GB of storage was amazing. No longer did I need fear hard drive failure and losing all my important email. Second, conversational email, where all messages in a single thread were combined, was amazing. No longer did I have to search through a large inbox to find related messages. Lastly, and probably most important, was searching. Filing email into folders always seemed absurd to me, but searching my mail history ended up being a perfect solution for me.
When Gmail was release, not all was roses; there were several criticisms leveled at the service, the most loudly voiced one was that the ad content displayed inside Gmail were selected based on the contents of your email. This criticism always struck me as a bit silly because email is transmitted across unsecured network connections and passes through multiple servers on the way to and from my inbox. Email has always been readable by anyone who wants to do so.
Nice history lesson you say, but what about that requirements document I mentioned in the title of this post? Like most things Google, it was likely very simple. I expect it grew out of a frustration with existing email clients and their limitations. This frustration likely led to two of the key features, email search and threaded conversations. But what about the huge storage space? How did this feature, which had been frustrating with existing providers, end up into the mix? It doesn't seem really obvious at first, until you remember Google wasn't providing Gmail out of the kindness of their heart... they had to make back a return on their investment.
Lets look at email usage around the time Gmail was introduced. At this time, it was popular to forward a large number of 'junk' emails of funny cats, videos and other large files as a means of sharing with your friends. Usually these emails were often half a MB or larger, so 20 of them would overflow an email box quickly. As useless as I felt these emails to be, they did reveal a lot about the person who sent them and often something about the recipient as well.
That history of sent and received email, especially when viewed over a long period of time, can be an excellent predictor of not only what a person currently likes, but of what they could be interested in when compared against users with similar conversations. This is a treasure trove for marketers because it contains data not just on a user's stated opinions but also on their actual behavior.
Without the large storage capacity, 20 garbage forwards could wipe out all of that customer information contained within that long email history. For Gmail to be successful as a platform for serving ads, for advertisers to truly know they're correctly targeting their ad buys, there had to be a great deal of data on each customer.
That brings us to the requirements document once again... it looks to have contained three items, two that greatly benefited users and one that benefited users and marketers. Over the last six and a half years since Gmail's introduction, it has proved itself to be one of Google's most successful products. If only we could all have the opportunity to elicit requirements that are so straightforward and so valuable.